Overclock.net › Forums › Intel › Intel CPUs › Haswell OC: Downclocking 2133+ RAM to 1600/1866 for Stable OC vs. Buying 1600/1866 RAM Outright?
New Posts  All Forums:Forum Nav:

Haswell OC: Downclocking 2133+ RAM to 1600/1866 for Stable OC vs. Buying 1600/1866 RAM Outright?

post #1 of 3
Thread Starter 
I'm trying to decide what RAM to buy for my 4770K build. I want to push the CPU as far as it can go on an H100i, and I've been reading and hearing all over the place that overclocking to stability in the 4.6+GHz range may require underclocking RAM speeds to the 1600/1866 MHz area if you've got RAM faster than that.

There's a lot of mention about higher RAM speeds allowing for stable overclocks when lowered, but there isn't any mention anywhere about the stability of 1600 MHz and 1866 MHz RAM when clocking up to 4.6+GHz. Is there a scenario where I'd have to underclock 1600/1866 MHz RAM to achieve a stable overclock?

Before I learned of this information, my plan was to get the highest speed RAM possible rated at 1.5V or less. That means 2133 MHz was my ceiling. My question is, all other things being equal, which of these scenarios would allow me to overclock the highest with an H100i thermal solution?

  1. 2133 MHz RAM at 1600/1866 Mhz
  2. 1866 MHz RAM at 1866 MHz
  3. 1600 MHz RAM at 1600 MHz

Basically what I can't find an answer to anywhere is if pushing clocks up past a certain point will require underclocking of 1600 MHz or 1866 MHz RAM.

What I'm also curious about is what comes first: limited overclock due to thermal throttling or due to memory speed? I'm just tossing thoughts out here, but my gut feeling tells me that thermal throttling comes first, I would need to be able to overclock very high before requiring an underclock of 1600/1866 MHz rated RAM, and that I would never get to overclocks that high in the first place because of thermal throttling.

My goal/fairy tale wish is 4.7 GHz, which I know will require a fair bit of luck in the silicon lottery, especially considering I have an H100i and not a water/coolant loop or a phase changer. If I end up being lucky, which one of those three options would work if I wanted the highest speed RAM of the three, and if took out that RAM and replaced it with 1600 MHz sticks, would I be able to overclock even higher? On an H100i's cooling ability?
Edited by LeMonarque - 7/12/13 at 6:27pm
VALKYRIE
(16 items)
 
  
CPUMotherboardGraphicsRAM
Intel Core i7-4770K ASUS Sabertooth Z87 ASUS GeForce GTX 780 DirecCU II OC Corsair Vengeance Pro 2x8GB DDR3-1866 (Silver) 
Hard DriveCoolingOSMonitor
Samsung 840 Pro Series 256GB Corsar Hydro Series H100i Windows 7 Home Premium 64bit ASUS PB278Q 
KeyboardPowerCaseMouse
Logitech G710+ Corsair AX760 Cooler Master CM Storm Stryker Gigabyte GM-M8000X 
Mouse PadAudioAudioAudio
XTrac PRO HS Audio-Technica ATH-M50WH Logitech Z623 ASUS Xonar DX 
  hide details  
Reply
VALKYRIE
(16 items)
 
  
CPUMotherboardGraphicsRAM
Intel Core i7-4770K ASUS Sabertooth Z87 ASUS GeForce GTX 780 DirecCU II OC Corsair Vengeance Pro 2x8GB DDR3-1866 (Silver) 
Hard DriveCoolingOSMonitor
Samsung 840 Pro Series 256GB Corsar Hydro Series H100i Windows 7 Home Premium 64bit ASUS PB278Q 
KeyboardPowerCaseMouse
Logitech G710+ Corsair AX760 Cooler Master CM Storm Stryker Gigabyte GM-M8000X 
Mouse PadAudioAudioAudio
XTrac PRO HS Audio-Technica ATH-M50WH Logitech Z623 ASUS Xonar DX 
  hide details  
Reply
post #2 of 3
downclocking your memory is perfectly fine.

if you understand the silicon lottery then you should know that there is ram chip lottery too. except the vendors plays the lottery game with memory chips, not you.

they test the memory modules, and if it is stable @ 2133 mhz, they slap on a sticker and sell it as 2133 mhz kit. if it's not stable at 2133 mhz, they test it at 1866 mhz (or other less common speeds), if it is stable at 1866 mhz, they slap a sticker on it and sell it as a 1866 mhz kit. if it is not stable at 1866 mhz... you get the idea.
Daily Workhorse
(15 items)
 
  
CPUMotherboardGraphicsRAM
Intel i5 4670K MSI Z87-GD65 Asus GTX 660 DC2-OC  G.Skill RipjawsX 4x4GB 1600 
Hard DriveOptical DriveCoolingOS
OCZ Agility 60GB none Noctua NH-U12P Windows 8 
MonitorKeyboardPowerCase
Dell U2312HM CoolerMaster Quick Fire CMStorm Red Corsair 650HX Lian Li PC-K9WX 
MouseAudio
Logitech G400 Creative X-Fi HD USB 
  hide details  
Reply
Daily Workhorse
(15 items)
 
  
CPUMotherboardGraphicsRAM
Intel i5 4670K MSI Z87-GD65 Asus GTX 660 DC2-OC  G.Skill RipjawsX 4x4GB 1600 
Hard DriveOptical DriveCoolingOS
OCZ Agility 60GB none Noctua NH-U12P Windows 8 
MonitorKeyboardPowerCase
Dell U2312HM CoolerMaster Quick Fire CMStorm Red Corsair 650HX Lian Li PC-K9WX 
MouseAudio
Logitech G400 Creative X-Fi HD USB 
  hide details  
Reply
post #3 of 3
High memory clocks can limit the overclock of the CPU, but there is no difference between running 1866 RAM at 1866 or 2133 RAM at 1866 - all the chip sees is 1866. My suggestion would be to buy 2133 RAM and then initially overclock your CPU with it set at 1600 or 1866. Once you get the CPU overclock dialed in, then you can start turning the RAM speed up. That way if memory isn't a problem, you'll be able to run at 2133. If you buy 1600 or 1866, that's all you'll get no matter what. And thermal limit will almost definitely come up before any kind of memory limit, at least without delidding.
New Posts  All Forums:Forum Nav:
  Return Home
  Back to Forum: Intel CPUs
  • Haswell OC: Downclocking 2133+ RAM to 1600/1866 for Stable OC vs. Buying 1600/1866 RAM Outright?
Overclock.net › Forums › Intel › Intel CPUs › Haswell OC: Downclocking 2133+ RAM to 1600/1866 for Stable OC vs. Buying 1600/1866 RAM Outright?